Hi Petra

The quiz activity only allows for feedback based on an individual question or on the final grade rather than at a category level.

What you are describing where different responses and pathways are taken depending on a responses to a set of questions sounds like the Lesson activity. This is fairly complex to setup but allows multiple pathways to be taken based on a user's responses.

If this looks too complex then using a quiz for each category of questions and providing feedback based on the quiz total is simpler.

There is also an option to Restrict Access to  a quiz based on the result of another quiz so you only allow a user to access the Edible plant quiz if they have successfully completed the mushroom quiz.

Regards